A cell is a **Maven/Gradle module** by default; in small repos a package guarded by ArchUnit rules is the starting granularity, with promotion to a module on the usual triggers (heavy optional deps, release cadence, ~2 kLoC). JPMS `module-info` SHOULD be used where the toolchain cooperates — it is the compiler-enforced form of the surface rule — with the ecosystem friction named honestly rather than wished away.

Cell manifest (annotation carrier, §5):

R-001 binding — flag at the seam, never in the veins:

Java's historical irony, handled with respect: the language *invented* the signature-level failure surface — checked exceptions — and the culture buried it under wrappers and lambda-hostility until `throws` clauses became lies. The Discipline does not resurrect them; it takes the modern equivalent the language finally grew:

`spec` carries the violated REQ URI; boundary rendering appends it (PROP-014 §2.6). **No `default` arm on a sealed `switch`** — the default clause silences the compiler's exhaustiveness check, the same graveyard move banned in the C++ Traditional guide; a new permitted subtype must break the build at every consumer.

**Annotations** — Java is the annotation culture, and the carrier exploits exactly the safe half of it:

Design: a tiny `specmark` artifact, `compileOnly`/`provided` scope, zero transitive dependencies, **`RetentionPolicy.CLASS`** — present in bytecode for T-syn/T-sem analysis, invisible to runtime reflection (aligned with the trunk's anti-reflection stance), and **`@Documented`** — the edges render in Javadoc, so the carrier doubles as the doc surface (the TS/Python simplification; the deliberate opposite of Go's hidden directives). The annotation's structure is compile-checked, which no comment carrier in the set can claim. No runtime processor exists or ever will. ≤3 edges per item or split.

A cell with `replaces=` ships a differential oracle: jqwik/QuickTheories properties driving both cells through the seam, asserting agreement modulo a documented divergence list, `@SpecVerifies`-tagged. Golden files follow the promotion protocol (CI never updates). **In-source xfail twin — Java can have one:** the profile ships a ~20-line JUnit 5 extension, `@KnownFailing("debt-id")`, with strict semantics — the annotated test *failing* is green, the test *passing* fails the run and forces promotion. `@Disabled` on known-failing tests is banned (it hides both regressions and healings — Go's `t.Skip` problem, here solvable). **Mockito is banned in cell tests** — reflection-based mocking is the `vi.mock`/`mock.patch`/gomock of Java, and capability injection makes it unnecessary; boundary tests may use it (MIT, fine there).

Javadoc on every exported element: behavior, the seam's error codes with their REQ URIs, nullness beyond the annotations, thread-safety and blocking characteristics, resource ownership. The `@Documented` specmark edges render alongside — provenance is visible where readers already look. Spec stays thin; duplication between Javadoc and spec is a defect on the spec side.

**First carrier note.** No Java exists in vibevm; no carrier is designated. Trunk and overlays ship genre-complete and unexercised under the carrier-relative house clause: rules remain DRAFT until a first Java carrier exists, and at its first milestone any rule without a conform check (or explicit `WISH` mark) is removed rather than carried as aspiration.